The goal of this proposal is to develop and test on-line fiber-optic chemical sensors for measuring gaseous and dissolved oxygen based on the quenching of the luminescence for immobilized metal-polypyridine complexes with oxygen. It is also proposed to explore the possibility of coupling these oxygen optrodes as transducers for developing highly sensitive glucose biosensor based on glucose oxidase. The specific aims of the Phase I research period are to design, synthesize, and characterize new and existing metal-polypyridine complexes with relatively long excited state life time (in microsecond range), high photochemical stability, and large emission quantum yields in order to evaluate their potential as luminophores. The selected luminophores will be impregnated or covalently attached to polymers known for their high and selective permeability for molecular oxygen. Preliminary in vitro evaluation of stability of the immobilized luminophores over extended periods of time will also be carried out. In the Phase II, comprehensive biocompatibility evaluation of these immobilized luminophores will be undertaken to adapt them to fiber-optic technology to integrate with the existing fluorometers and calibrators to develop a compact package for biomedical applications.